activated sludge Articles
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Study of kinetics of degradation of cyclohexane carboxylic acid by acclimated activated sludge
Activated sludge contains complex microorganisms, which are highly effective biodegrading agents. In this study, the kinetics of biodegradation of cyclohexane carboxylic acid (CHCA) by an acclimated aerobic activated sludge were investigated. The results showed that after 180 days of acclimation, the activated sludge could steadily degrade >90% of the CHCA in 120 h. The degradation of CHCA ...
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An integrated system for wastewater COD characterization and a case study
The guidelines of Activated Sludge Model (ASM) can make the use of modeling more straightforward and systematical. Therefore, this paper aims to develop a guideline for wastewater COD characterization. Four physical-chemical methods were compared experimentally for wastewater characterization in this paper and flocculation + 0.45 μm membrane filtration combining respirometry was selected to ...
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Low temperature microwave and conventional heating pre-treatments to improve sludge anaerobic biodegradability
This paper presents the results of lab-scale experiments on low temperature thermal pre-treatment (less than 100 °C) prior to anaerobic digestion of sewage sludge. Two heating ways, microwave heating (MH) and conventional heating (CH), and two types of sludge, primary and waste activated sludge, were compared under the same experimental conditions. The degree of solubilisation produced ...
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Evolution of the sewage treatment plant model SimpleTreat: Use of realistic biodegradability tests in probabilistic model simulations
Given the large number of chemicals under regulatory scrutiny, models play a crucial role in the screening phase of the environmental risk assessment. The sewage treatment plant (STP) model SimpleTreat 3.1 is routinely applied as part of the European Union System for the Evaluation of Substances to estimate the fate and elimination of organic chemicals discharged via the sewage. SimpleTreat ...
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Comparison of biodegradation performance of OECD test guideline 301C with those of other ready biodegradability tests
The OECD Guidelines for the Testing of Chemicals lists seven types of tests for determining the biodegradability of chemical compounds (301A–F and 310). In this study, we compared the biodegradation performance of test guideline (TG) 301C, which is applied in Japan's Chemical Substances Control Law, with the performance of the other six RBTs listed in the guidelines. TG 301C specifies use of ...
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Impact of copper and cadmium on aerobic and anaerobic digestibility of sonicated sludge
The effects of the introduction of a sludge reduction process such as ultrasound on batch aerobic and anaerobic biodegradability after exposition to two metals (copper and cadmium) were investigated. The specific energy of ultrasonic treatment applied to the sludge was 200,000 kJ kg TS-1. Ultrasonic treatment led to floc size reduction and to organic matter solubilization. Low copper (qmax ...
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Thermal hydrolysis of waste activated sludge at Hengelo Wastewater Treatment Plant, The Netherlands
The thermal hydrolysis process (THP) is a sludge treatment technique which affects anaerobic biodegradability, viscosity and dewaterability of waste activated sludge (WAS). In 2011 a THP-pilot plant was operated, connected to laboratory-scale digesters, at the water board Regge en Dinkel and in cooperation with Cambi A.S. and MWH Global. Thermal hydrolysis of WAS resulted in a 62% ...
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Improved methane production from waste activated sludge with low organic content by alkaline pretreatment at pH 10
Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the ...
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Evaluation of biotreatability of ionic liquids in aerobic and anaerobic conditions
The aim of our study was to set up an approach for reliable biotreatability assessment of ionic liquids (ILs). As a case study, two different ILs were selected: pyridinium-based 1-butyl-3-methylpyridinium dicyanamide ([bmpyr][dca]) and imidazolium-based 1-butyl-3-methylimidazole tetrafluoroborate ([bmim][BF4]). Toxicity in aerobic conditions was determined by measurement of inhibition of oxygen ...
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Evaluation of the aerobic and anaerobic biodegradability of the antibiotic norfloxacin
The purpose of studying the biodegradability of pharmaceutical compounds is to evaluate their behaviors in relation to the treatment processes generally used in domestic and industrial wastewater treatment plants. The antibiotic norfloxacin was found to be a recalcitrant compound. The studies conducted showed norfloxacin removal rates of 12% and 18% when biomasses from treatments ...
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BM Respirometry Study Toxicity & Biodegradability of a Refinery polymer stream, when treated in the activated sludge process of the plant - Case Study
This “batch system” respirometer consists of: a single thermostatically controlled vessel, divided into two interconnected compartments with closed recirculation loop between the two. A constant air flow is supplied via a ceramic diffuser in the conditioning compartment, and a combined oxygen/temperature sensor in the reaction compartment controls the DO and temperature. Both ...
By SURCIS, S.L.
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Elimination of selected pharmaceuticals by biosolids from municipal wastewater treatment plants: importance of modest pH change and degree of mineralization
Lab-scale batch experiments with biosolids collected from a full-scale activated sludge system (AS) and a pilot-scale membrane bioreactor (MBR) were carried out to investigate the mechanisms of elimination of 5 acidic pharmaceuticals and 2 neutral pharmaceuticals. Batch elimination experiments were conducted under the conditions of pH of 6 and 7, and a great impact of pH on elimination of ...
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Biodegradability Study on Filming Amines - FINEAMIN 06 - Case Study
Study conducted by Eurofins Ecotoxicologie France In a study conducted by Eurofins Ecotoxicologie France, FINEAMIN 06 has proved to be readily biodegradable, with a biodegradability rate of 90% after 28 days of test. To be considered as ready biodegradable, a product (mainly, a pure substance) must show a biodegradation rate of at least 70% in the 10-day interval which has to fall within the ...
By Fineamin SA
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Fate of organic matter during moderate heat treatment of sludge: kinetics of biopolymer and hydrolytic activity release and impact on sludge reduction by anaerobic digestion
Temperature-phased anaerobic digestion with a 50–70 °C pre-treatment is widely proposed for sludge. Here, such a sludge pre-treatment (65 °C) was studied against the physical, enzymatic and biodegradation processes. The soluble and particulate fractions were analysed in terms of biochemical composition and hydrolytic enzymatic activities. Two kinetics of organic matter ...
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